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Signal speed and myelin

The time a nerve signal takes is the distance divided by the speed. Myelin insulates the axon, and the signal jumps between the gaps, so the speed becomes much higher. Without myelin the speed can be around one meter per second. With myelin it can be around one hundred meters per second. Those are the kinds of numbers the problems use. A reflex is fast for another reason too: the signal goes via the spinal cord and skips the detour through the brain. Hormones are slower. They are carried in the blood and act throughout the body.

t=svt = \frac{s}{v}time for the signal

Symbols

sslengthm
vvspeedm/s
tttimes

Example

One meter without myelin, 1 m/s: t=1/1=1t = 1/1 = 1 s =1000= 1000 ms.

One meter with myelin, 100 m/s: t=1/100t = 1/100 s =10= 10 ms.

Convert to milliseconds at the end if the problem asks for it. 1 second is 1000 milliseconds.
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Part of Biology 2: The nervous system and hormones.